Low normal vs. high normal confusion? Help!!

I've got a '03 Trek Liquid that I 'think' has high normal shifting. That is, if I push on my thumb of my rear quick Deore shifter, I force against spring tension and the chain moves up to a larger rear sprocket, this is high normal, correct?

I'd like to upgrade my LX rear derail to a XT, which one do I need to order? M751 or M760 Will the newer style low normal rear derail (which works opposite to what I currently have, right?) work with my current '03 Deore shifters or do shifters have to be upgraded with the newer low normal derails?

Also, if either type will work fine on my bike, low or high normal, which would be the better type to get?

Low normal rear der. will work with your shifts but your shifting will be reversed (pushing the lever moves you into harder gears.

Its really preference as to which one you want to use. I like rapid rise personally on my XC bike because it allows me to click up one gear at a time easily while climbing a hill. On my Downhill bike and urban bike's i like non rapid rise as they can take hits better and i'm usually going down the hill so clicking into harder gears is done one by one.

Based in your description, you are correct that you currently have a high-normal setup.

You can install a low-normal rear derailleur using your current shifters, no problem. If you have a gear indicator, the display will work opposite how it does now, but that's it! A thumb press will take the chain to the next higher gear (next smaller cog). Trigger release will unspool cable and allow the derailleur to advance towards the home position (the biggest cog).

My own preference for Rapid Rise derailleurs was the ability to upshift multiple gears in one press of the thumb -- great for topping a climb or transitioning into a quick descent.

Others hate Rapid Rise for exactly this reason -- they would much prefer the ability to shed multiple gears in a single press.

It seems to be an endless debate; I'm sure a quick search in this forum would turn up more opinions than you care to read.

I placed my order just now( on sale Jenson XT M751Long at $49) and decided to stick with my current high normal shifting. There are a lot of steep, shortly spaced hills where I usually ride and I find being able to quick click to smaller sprockets on the down hills and being able to more positively engage a larger rear sprocket more important to me ....I think. Really hard to tell since I've never tried or felt how RapidRise actually works. Plus not to mention reverse shifting would whack me out in the head for several outings; don't really feel like relearning mid season, heh.